All space faring nations devote a portion of their resources to exploring the
solar system. NASA has a forty-year history of robotic missions reaching into deep space
for a better understanding of our origins, the evolution of our planet, and our destiny.
For the past decade, NASA has placed considerable emphasis on the search for life beyond
Earth. Missions to the rocky terrestrial planets and the moons of the gas giants seek
answers to the question: Are other worlds in the solar system habitable by simple
organisms? By framing its search objective in this way, NASA motivates investigations of
the fundamentals of what makes a planet an abode for life, and what ingredients are
required for the origin and evolution of life. In this lecture, we focus on the
strategies and results of the search thus far. We will discuss recent scientific missions
to Mars, Europa, and Titan.

Dr. Dan McCleese is the Chief Scientist for NASA's Mars Exploration
Program at JPL. In this role he has worked with NASA and the international science
community to establish the current science strategy for exploring Mars. Dan's personal
science interests are focused on acquiring and interpreting climatological data sets for
the terrestrial planets. Specific research topics include development of the first
climatology of cloud height for Earth, upper atmospheric cloud and thermal structure of
Venus, and, at present, the modern climate of Mars. He is the Principal Investigator for
the Mars Climate Sounder on the Mars Reconnaissance Orbiter to be launched in 2005. In
this investigation, measurements of atmospheric water vapor, temperature and condensates,
and the energy balance of the polar caps are emphasized. Dr. McCleese was a Fulbright
Scholar at Oxford University receiving a D.Phil. degree in Atmospheric Physics.